Bottom seal for deep-well pumps



Jan. 29, 1957 E. E. sTEvENsON BOTTOM SEAL FOR DEEP-WELL PUMPS Filed Aug. 16, 1954 [mamy: @W4/@ 57am/50M gf MM m United Patent f BOTTOM SEAL FR DEEP-WELL PUMPS Edward E. Stevenson, Whittier, Calif., assignor to United States Steel Corporation, a corporation of New `ersey Application August 16, 1954, Serial No. 449,959

2 Claims. (Cl. 166-195) This invention relates to an improved seating mandrel for deep well subsurface pumps.

Commonly a subsurface pump carries a mandrel, the outer face of which seats Within a shoe fixed to the tubing. To prevent leakage the fit between the mandrel and shoe should afford a fluid-tight seal. The usual practice has been to include either a soft metal insert or a resilient sealing ring of rubber or the like in the seating face of the mandrel. The insert or ring conforms to the shape of the shoe and thus furnishes the necessary seal. However, both arrangements have disadvantages. Metals like babbitt which readily form a good seal are structurally Weak, while stronger metals, such as brass or bronze, do not always provide a satisfactory seal. The usual resilient ring provides an excellent seal, but it is likely to drop loose from the mandrel whenever the pump is pulled from the well. If a loose ring later gets inside the pump, it causes damage.

An object of my invention is to provide an improved seating mandrel which overcomes the disadvantages of previous arrangements, that is, one which affords both a tight seal and suilcient mechanical strength and yet cannot drop loose.

A more specific object is to provide a seating mandrel which carries a resilient sealing ring embedded between two metal rings that positively prevent its accidental removal.

In accomplishing these and other objects of the invention, l have provided improved details of structure, a preferred form of which is shown in the accompanying drawing, in which:

Figure 1 is a vertical sectional view of the lower portion of a subsurface pump` which is equipped with a mandrel constructed in accordance with my invention `seated within a shoe;

Figure 2 is a partial view similar to Figure 1, but on a larger scale, showing the mandrel seated; and

Figure 3 is a view similar to Figure 2, but showing the mandrel unseated.

Figure 1 shows the lower portion of a pump which includes a barrel and a standing valve 12. The pump is located near the lower end of a tubing string 13, which carries a shoe 14. The interior of the shoe has an upwardly flared seating face 15. These parts can be of any standard or desired construction, and hence are not described in greater detail.

The mandrel of my invention comprises a nut 16, a tubular body 17, and a metal insert composed of upper and lower annular sections 18 and 19. 'Ihe nut 16 is threadedly attached to the lower end of the pump barrel 10 and at its upper end supports the standing valve 12. The lower portion of the nut is internally screw-threaded and preferably its bottom face is internally beveled, as indicated at 20. The body 17 is threadedly attached to the lower end of the nut 16 and it has a downwardly tapered external seating face 21 which cooperates with the seating face on the shoe 14 to seat the pump. The lower end of the body preferably carries retaining lingers 22 which engage an internal shoulder 23 on the shoe 14 for holding the pump in its seated position. Immediately above its seating face 21 the body is recessed, with the 2,779,4.20l Patented Jan. 29, 1957 ICC lower edge of the recess preferably having an overhanging lip 24. The sections 1S and 19 of the insert it between the beveled face 2i) of the nut and the lip 24 or" the body. The outside face of the lower section 19 is tapered and forms a continuation of the seating face 21 on the body 17.

The lower outside edge of the upper section 18 of the insert has a downwardly extending lip 25. The upper edge of the lower section 19 is recessed as indicated at 26. The rear face 27 of the recess 26 is conical. The lip 25 overhangs the recess 26 leaving a gap 28 between this lip and the lower section 19. A resilient ring 29 is housed within the recess 26 and projects through the gap Z8. When the pump is seated as shown in Figures 1 and 2, the conical surface 27 forces the ring 29 into a fluidtight sealing engagement with the seating face 15 of the shoe 1li. The cross-sectional diameter of the ring 29 is greater than the width of the gap 28. Consequently when the pump is unseated as shown in Figure 3, the lip 25 prevents the ring from dropping loose and positively retains it on the mandrel.

While l have shown and described only a single embodiment of the invention, it is apparent that modications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

l. A seating mandrel for a subsurface pump comprising a nut adapted to be attached to the pump, a tubular body attached to the lower end of said nut and having a downwardly tapered seating face, a lip integral with said body at the upper extremity of said seating face, said lip being spaced from said nut, upper and lower annular insert sections mounted on the exterior of said body in the space between said lip and said nut, both said sections having downwardly tapered seating faces forming an extension of the seating face on said body, one of said sections having an annular recess adjacent the other section, an integral lip on said other section overhanging a portion of said recess leaving a gap between the respective seating faces of the two sections, a resilient ring housed in said recess and being of greater cross-sectional diameter than the width of said gap and positively retained in said recess by said second named lip, and means on one of said sections forcing a portion of said ring through said gap.

2. A seating mandrel for a subsurface pump comprising a nut adapted to be attached to the pump, a tubular body attached to the lower end of said nut and having a downwardly tapered seating face, a lip integral with said body at the upper extremity of said seating face, said lip being spaced from said nut, upper and lower annular insert sections mounted on the exterior of said body in the space between said lip and said nut, said lower section having an annular recess in its upper outer portion adjacent said upper section, an integral lip on said upper section overhanging a portion of said recess leaving a gap between the lower edge of said second named lip and said lower section, said lower section and the exterior of said second named lip having seating faces separated by said gap and forming an extension of the seating face on said body, a resilient ring housed in said recess and being of greater cross-sectional diameter than the width of said gap and positively retained in said recess by said second named lip, and means on said lower section forcing a portion of said ring through said gap.

References Cited in the le of this patent UNITED STATES PATENTS 2,054,322 Hoferer Sept. 15, 1936 2,417,494 Hoof Mar. 18, 1947 2,456,356 Aber ca f Dec. 14, 1948 

